Hydraulic drill



p 11, 1956 J. s. SCHROEDER 2,762,339

HYDRAULIC DRILL Filed Dec. 4, 1952 5 Sheets-Sheet 1 IN VEN TOR. H John .S. Schroeder BY W fa 7+ [224W HIS A TTORNEYS Sept. 11, 1956 .1. s. SCHROEDER 2,

HYDRAULIC DRILL Filed Dec. 4, 1952 5 Sheets -Sheet 3 I A A INVE R. JohnSSchro er H/S ATTORNE Y5 Sept. 1956 J. 5. SCHROEDER 2, 9

HYDRAULIC DRILL Filed Dec. 4, 1952 5 Sheets-Sheet 4 INVENTOR. John 5. Schroeder BY M, mpa fifim HIS ATTORNEYS p 11, 1956 J. 5. SCHROEDER 2,762,339

HYDRAULIC DRILL Filed Dec. 4, 1952 5 Sheets-Sheet 5 INVENTOR. John S. Schroeder BY M-f- Hafi I /3AM HIS ATTORNEYS United States Patent HYDRAULIC DRILL John S. Schroeder, Edgeworth, Pa., assignor to Schroeder Brothers, a Pennsylvania partnership whose members are A. Reed Schroeder, John S. Schroeder,'William E. Schroeder, and Frank C. Schroeder, Jr.

Application December 4, 1952, Serial No. 324,015

1 Claim. (Cl. 121-34) This invention relates to an hydraulic drill in which the drill proper is driven by an hydraulic motor having a rotor located in a rotor chamber. The invention relates particularly to hydraulic drills for drilling holes into coal or other material for receiving an explosive charge.

Heretofore it has been the general practice to drive coal drills by the use of an electric motor. This practice has several disadvantages which are overcome by the employment of an hydraulic drill in accordance with the present invention. Electric motor-driven drills are likely to cause sparks and thereby set off an explosion. There is also the danger of the operator receiving an electric shock. Furthermore, when a drill operated by an electric motor and gears is stalled due to the drill sticking in the coal or other material, it subjects the operator to a mechanical kick or vibration due to the sudden stopping of the drill. All of these disadvantages are overcome by the present invention.

My hydraulic drill is relatively simple in construction and although powerful enough for rapidly drilling holes, is sufi'iciently light so that it can be easily held by one man even when it is stalled due to sticking of the drill in the material being bored.

In the accompanying drawings which illustrate a preferred embodiment of my invention.

Figure 1 is a front elevation of the hydraulic drill;

Figure 2 is a plan view of the hydraulic drill;

Figure 3 is a side view of the hydraulic drill;

Figure 4 is a longitudinal vertical section taken on the line IV-IV of Figure 2;

Figure 5 is a transverse section taken on the line V--V of Figure 4;

Figure 6 is a transverse section taken on the line VI-VI of Figure 4;

Figure 7 is a transverse section taken on the line VII-VII of Figure 4;

Figure 8 is a longitudinal section taken on the line VIIIVIII of Figure 7;

Figure 9 is a horizontal section taken on the line IXIX of Figure 1, the valve for controlling the flow of actuating fluid to and from the rotor chamber being in inoperative positon so that the fiuid does not flow through the rotor chamber;

Figure 10 is a view similar to Figure 9 except that the valve is in operative position, causing the oil to flow through the rotor chamber so as to operate the rotor and the drive shaft and drill operated by the rotor.

Figure 11 is a vertical section taken on the line XI-XI of Figure 1; and

Figure 12 is a diagrammatic illustration of means for supplying oil or other motive fluid under pressure to the hydraulic motor and returning it to a tank for recirculation.

Referring first to Figure 12, the hydraulic drill designated generally by reference numeral 2 is provided with handles 3 and 4 adapted to be gripped by the operator Oil in tank 5 is withdrawn through pipe 6 by pump 7 driven by an electric motor 8, and is passed under pressure through a conduit 9 controlled by relief valve 10 to the rotor chamber of the hydraulic drill 2. After passing through the rotor chamber, thereby actuating the rotor and the drive shaft and drill connected thereto, the oil returns to the tank 5 through conduit 11 for recirculation. The present invention does not relate to the means for supplying oil under pressure to the hydraulic motor. The description thereof is given merely for purposes of explaining the operation of the invention.

Referring now more particularly to the other figures, the invention comprises an hydraulic motor, indicated generally by reference numeral 14, and a control valve operating in a, valve chamber in a valve casing 15 for controlling the flow of oil through the motor as explained hereafter.

The hydraulic motor 14 comprises a drive shaft 16 mounted in a bearing 17 located in a bore 18 formed in a front head 19. The shaft also is mounted in a bearing 20 located in a bore 21 formed in a rear head 22. The right-hand end of the shaft (as viewed in Figure 4), bears against a thrust bearing 23 located in a bore in an end cap 24. A collar 25 secured to the shaft 16 by a pin 25a transmits any thrust of the shaft towards the front of the drill against a thrust bearing 26 which is held in an enlargement 21a of the bore 21 adjacent its open end. A spring 25b holds the pin 25a in place. A gland 27 is provided at the left-hand end of the shaft to seal the shaft. Bolts 30 secure'the cap 24 to the rear'head 22.

The drive shaft 16 is keyed to an inner gear rotor 31 by a key 32 so as to allow sliding movement between the shaft and the rotor 31. The rotor 31 is gear shaped and fits within an outer-gear shaped rotor 33, the number of teeth on the inner rotor 31 being one less than the number of teeth on the outer rotor 33. The outer rotor 33 fits within an eccentric ring 34, which in turn fits within an outer ring 35. The inner gear rotor 31 and the outer gear rotor 33 are located eccentrically to each other and when oil under pressure is introduced into the space 36 between the inner and outer rotors, which space forms a rotor chamber for the inner rotor, both the inner and outer rotors rotate in the same direction but at different speeds. The construction and operation of rotary hydraulic motors having an inner and an outer gear rotor similar to the rotors 31 and 33 herein described is shown per se and therefore need not be described in further detail.

A bearing plate 38 is located within the ring 35 and between the front head 19 and the inner rotor 31, the outer rotor 33, and the eccentric ring 34. Bolts 39 secure the front head 19, the bearing plate 38, the eccentric ring 34 and the rear head 22 together. As shown in Figure 6, the bearing plate 38 is provided with an inlet port 40 and an outlet port 41, each extending through the bearing plate. As shown in Figure 7, the front head 19 is provided with an inlet port 42 and an outlet port 43, the ports 40 and 42 communicating with each other and the ports 41 and 43 communicating with each other. An inlet passage 45 connects port 42 with a valve chamber 46 formed in valve casing 15. An outlet passage 47 connects outlet port 43 with a valve chamber 48 in valve casing 15.

Referring now to Figures 9, .10 and 11, the valve casing 15 has a main valve chamber 50, an inlet valve chamber 46 and an outlet valve chamber 48. Oil under pressure is supplied through conduit 9 and fitting 51 to the inlet chamber 46. A fitting 52 connects the outlet valve chamber 48 with the return conduit 11. A hollow valve 53 is slidable within the valve chamber 50 and is provided with ports 54. A spring 55 urges the valve 53 to the left, as viewed in Figure 9. A valve stem 55a passes through a gland 56 and at its outer end is received in a cup 57 and is secured to the cup by a cotter pin 58. The cup has trunnions 59 which are received in slots 60 formed in the ends of a forked arm 61 which is secured by a screw 62 to a shaft 63. The shaft is mounted for rotation in a hearing 64 carried by a housing 65 secured to the valve casing 15. A lever 66 is secured to the shaft 63 by a screw 67.

When the lever 66 is in the position shown in Figure 9, the spring 55 forces the valve 53 to the left so that oil under pressure in chamber 46 flows through ports 54 into the interior of the valve and then flows through outlet chamber 48 and return conduit 11 without passing through the rotor chamber 36. This is due to the fact that the pressure in the return pipe 11 is less than that in the rotor chamber 36. When the parts are in the positions shown in Figure 9, the rotor 31 does not rotate, nor does the drive shaft 16.

When the lever 66 is moved to the operative position shown in Figure 10, the valve 53 is moved to the right so that ports 54 are cut off from inlet chamber 46. The oil flows from chamber 46 through passage 45, port 42, port 40, into the rotor chamber 36, and rotates the rotors 31 and 33 and the drive shaft 16. Oil flows out from the rotor chamber 36 through port 41, port 43, passage 47, valve chamber 48, and through the return conduit 11.

It will be noted that the lever 66 which controls valve 53 is located adjacent to thehandle 3 which, together with handle 4, are used by the operator to holdthe hydraulic drill. It will be seen that the position of the handle 66 is such that it can be operated by the same hand which grips the handle 3 without releasing the grip on thehandle. This greatly facilitates operation of the drill.

The outer end of the drive shaft 16 is provided with a notch 68 adapted to receive a key 69 and with flats 70 for securing a chuck to the drive shaft. The chuck receives and supports the drill proper in a known manner.

The invention is not limited to the preferred embodiment but may be otherwise embodied or practiced within the scope of the following claim.

I claim:

A hydraulic drill comprising a housing, a hydraulic motor having a rotor located in a rotor chamber in the housing, a drive shaft adapted to be connected at one end to a drill and extending through one side of the housing and the rotor to the opposite side of the housing, the shaft being slidably connected to the rotor, a thrust hearing at the end of the shaft away from the drill, a cap on the housing forcing the thrust plate against the end of the shaft so that the end of the shaft absorbs the thrust d veloped in forcing the drill into the work, a thrust collar on the shaft and secured against movement along the shaft towards said thrust bearing end, a thrust plate surrounding the shaft and supported in the housing against the thrust collar so that the thrust plate and thrust collar withstand thrust developed in withdrawing the drill from the work.

References Cited in the file of this patent UNITED STATES PATENTS Slomer Mar. 24, 1953 

